Admit it; you’ve done this before too. I’m sure I’m not the only one.
I’m at a restaurant having a meal with my family. The server brings the food out, distributes the dishes to each person, and checks to see if everything is in good shape. We confirm, and she replies, “Great, enjoy your meal!” I respond, “Thanks. You too!”
How embarrassing! If I had stopped to think about what I was going to say, I would quickly realize that she was going to continue working, not sit down and enjoy a meal, but I did what came naturally and returned the pleasantry in kind.